“Since” and “Because”–What’s the Difference Between These Confusing Words?

In my recent post on the blog of Nonfiction Authors Association (NFAA), an author asked about confusing words this way:

Barbara, I’d love to see you do an article on the difference between “as” and “since” and “because.”

Here’s a summary of what my research told me.

Both “because” and “since” imply cause. They can be interchangeable when “since” means “for the reason that.” e.g., “Since my dog needs exercise, I take him for a walk.” e.g., “I walk every day because my dog needs exercise.”

One source suggests using “because” when the reason is the most important part of the sentence and “since” or “as” when the reason is already well known and is less important. e.g., “The match was cancelled because it was raining.”

I endorse this as an important distinction and use it myself.

Note that “since” also refers to a time frame. But look at this example. “Since we ate lunch, we had lots of energy.” Do you see how this statement is ambiguous? Does it mean “from the time we had lunch” or “for the reason that we had lunch”?

To avoid confusion, I recommend using “because” when your meaning relates to “cause” and “since” when it’s a factor of time. Keep the meanings distinct; it’s a good way to add clarity to your writing and power to your pen.